It may be up to a year before the Defence Force can get back into its Wellington headquarters after Monday's earthquake caused structural damage.

Some dairy farmers in the South Island might have to dispose of their milk due to road closures and other issues.

Queen Elizabeth II has sent a message of condolence to the Governor-General of New Zealand.

Acting Civil Defence Minister Gerry Brownlee says the cost of the earthquakes was still to emerge, but it would be in the billions of dollars.

Civil Defence aims to rescue 600 stranded tourists from Kaikoura today.

Donald Trump has called John Key and offered his sympathies over the earthquake and spoke about the TPP, and Sir Bob Charles.

English tourist had just turned in for the night when the earthquake struck. Now the terrified visitor is desperate to get home.

More than 1700 tremors have rocked central New Zealand since Monday - but this constant shaking is normal says scientists.

COMMENT: The navies of the United States, Australia and Canada are joining New Zealand's earthquake relief effort.

Vital supplies are being flown in as Kaikoura has less than 24 hours of drinking water left.

Most phone services affected by yesterday's earthquake have now been fixed, Vodafone says.

A mercy mission into rural quake-hit Marlborough has led to donations for farming communities and offers of help.

Two cattle and a calf which survived yesterday's earthquake should be allowed to retire and live out their days in a sanctuary, animal rights group Peta says.

Red Cross is providing psychological support to communities affected by this week's earthquake, as people prepare to spend another night in welfare centres.

Tourism operators say there have been no reports of cancellations following the earthquakes but the industry is in damage control because of potential damage to NZ's image.

WATCH: When Ben Todd saw water rising towards his family home he knew there was only one thing to do.

Learn from Christchurch and subsidise businesses hit by the devastating Kaikoura earthquake, former mayor Sir Bob Parker has told the Government.

A number of schools have been closed due to flooding, affecting some students due to sit exams after afternoon.

Steven Joyce has been charged with putting together a "business continuity package" for Kaikoura.

Defence Force sends hundreds of staff plus planes and ships to earthquake-affected south.

Three blokes in a 4WD have headed into big country searching out those needing help in the wake of the Kaikoura Earthquake.

Our photographers and reporters share some of the images captured after yesterday's quakes.

Mid Canterbury farmers are on standby to take dairy cows from quake-affected North Canterbury dairy farmers.

Helicopters from US and Malaysia will help out in Kaikoura, says PM John Key.

New Zealand Post is warning that some mail will be delayed in areas hit by this week's earthquakes.

Several cars drove past an unwell and elderly quake victim, dressed in her pyjamas as she struggled to higher ground with her walking

Tourism leaders fear the image of New Zealand as a destination will be harmed by the earthquakes.

Preliminary modelling suggests that the earthquake was caused by a rupture of a northeast-striking fault t, but this may be a more complex event.

Richie McCaw, who has been airlifting stranded tourists out of Kaikoura, says the devastation from the air looks "pretty crazy".

Aftershocks continue around Kaikoura this morning.